Despite fans' wishes for the two to become an item, the costars are just friends, Gordon-Levitt, 31, insists in the September issue of Playboy.

"We've been friends for 10 years. She loves movies, music and art, and she's incredibly knowledgeable about that stuff," he says.

"She's turned me on to so many movies and so much good music. It's fun just so have conversations, watch movies with her."

Joseph Gordon-Levitt

Courtesy Playboy / Justin Stephens

Although Gordon-Levitt landed a role on 3rd Rock from the Sun at an early age – "I played baseball, did gymnastics, took piano lessons and started acting as just another one of the things I did. I wasn't pressured into it. But it was acting I loved," he says – it was his love of cinema that guided the actor toward a career on the silver screen.

"As a teenager in the 1990s I loved the spike of indie films coming through Sundance, and films like Pulp Fiction, Big Night, Sling Blade, Trees Lounge and Swingers," says Gordon-Levitt, who this summer is being seen in The Dark Knight Rises and in November will be in Lincoln, with Daniel Day-Lewis.

"I went to school, quit acting for a while, and when I came back everyone wanted me to do another TV show and make more money. I didn't want to," he goes on to say.

"I made a decision that I was only going to do work that inspired me creatively, not what was supposed to be good for my career."